Quantitative dynamics of larch caterpillar (Dendralimus superans [Buller]) and the biological control

Abstract

The relationship between pest population and other factors is rather complex within the forest ecosystem. A number of environmental factors, such as extreme climatic conditions, infection of natural enemies, may cause the death of pest insects directly. The effect of these factors reflects basically the situation and cause of death of insects at different stages of entire process of growth and development, so that they may be employed as the basic records of the quantitative dynamic of the population, and are of important value to the study of population quantitative dynamics of pests. Since Morris and Miller (1954) applied the life table technique to study natural population of insects, the insect life table technique has becoming an important means for the study of quantitative dynamics of pest populations. In foreign countries, the study of the life table of forest pest began in 50 year’s already. Moreover, the results of investigation were applied to the productive practice, such as the spruce budworm (Chorisloneura fumiferana Clemens), winter moth (Opperophlera brumata Linnaeus), while in our country, the quantitative dynamics of many forest pests were not investigated. The larch caterpillar is one of the great pest of larch plantation in China. Every year, the outbreak of this pest occur in some places, causing large economic loss. Many studies were performed on the biological and chemical controls, but the investigation on quantitative dynamics of the natural population of larch caterpillar was lacking. Since 1980, we studied the quantitative dynamics of the natural population of larch caterpillar in Shangzhi County, Heilongjiang Province and worked out life tables of two generations.